1 Shallow Pattern of Tire not Suitable for Expressway driving
    The tire pattern is not only for beauty's sake. It also has the functions of drainage, brake and the heat dissipation. Pattern too shallow, the drainage function will be reduced and likely to drift of water when there is water on the road section and the brake performance shall also be reduced. Especially when the car runs in long distance and high speed, the tire crown temperature can be very high. The emergency brakes at this very time shall easily cause tire crown contusion and lead to the danger of tire burst.
    Besides, heat dissipation performance will also be reduced when the tire pattern is shallow. The temperature accumulated inside the tire can not be let out in time and it will cause tire burst after some extent. Tire industry has a jargon  "the enemy of tire, temperature is" to prove the importance of heat dissipation. So be sure not to go to expressway for long distance driving when pattern tire is too shallow.

2 Tire with broken sides cannot go to expressway
    70% traffic accidents are concerned with tires, and more concerned with the sides of tires. In fact, the broken side of tires cannot go to expressway, and even normal driving can also exist many potential dangers. This is also the reason why tire manufacturers set the rule that tires with broken sides cannot be repaired and be used and should be changed into new tires.

3 Slashed tire crown or repaired tire are not suitable for expressway driving
    For safety's sake, cut tire crowns and repaired ones should be replaced if condition permits. If not, one should be more careful when driving.
Besides, tires with serious worn crown and worn tires in the middle and shoulders because of higher and lower tire pressure are not suitable for expressway driving either.
    In fact, besides the cautions before start, car owners should also pay more attention to the basic knowledge of tires maintenance.
    First, control tire pressure. Actual tire pressure has a great influence on tire life. High or low pressure can both bring great damage. The car owners should check tires once a week and see whether tire pressure is normal or not. At the same time, they should not forget to check the tire pressure of spare tire. 
    Second, when drive cars on the road every day, projecting from a broken glass and nails and other sundries into the tire is unavoidable. These seemingly simple things will gradually go deep. If in another, there will be possible to have a flat tire. One should often check and remove the stone and sundry adhering to tire patterns, check tire wear. Once tire wear replacement instructions mark appears, new tire should be replaced immediately in case of danger.
    Third, pay attention to tire ageing problems. Many people think that when tire wear to tread smooth, the replacement of tire can become necessary. Actually, the tire has its life of usage. Car manufacturers usually make tire usage life three years. If you need to change your worn tires, you'd better change with two or four at once, and choose those with the same pattern in order to keep balance of driving.